Closure with elastically deformed part at screw threads

ABSTRACT

A closure has a first screw thread ( 11 ) capable of cooperating with a second screw thread formed by a container intended to receive the closure. An elastically deformed part ( 28, 31 ) is capable, when the first ( 11 ) and second screw threads are engaged, of keeping the closure bearing elastically on the container in at least one direction oriented radially with respect to the closure, so as to improve the holding and working of the closure on the container.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a closure of the threadedclosure type, capable of being removably mounted on a container,particularly in the form of a glass jar, a bottle, a pot or some othershape. The invention is specifically suited to the closure of glass jarssuch as those used for packaging cosmetic care creams.

[0003] 2. Description of the Related Art

[0004] In the field of cosmetics, particularly in the field of carecreams, it is relatively commonplace to make use of glass jars. Thesejars are generally closed by a plastic lid having a screw thread capableof cooperating with a corresponding screw thread provided on an externalsurface of the jar in the vicinity of an opening delimited by a freeedge.

[0005] One of the problems encountered with this type of packagingarises due to the large clearance existing between the jar and itsplastic cap, which clearance is essentially due to the manufacturingtolerances of the glass screw thread, which are very wide. Suchclearance leads to problems with the airtightness and keeping of thecream contained in the jar. Furthermore, it is not very well received bythe consumers.

SUMMARY OF THE INVENTION

[0006] Thus, one of the objects of the invention is to provide a closurewhich completely or partially solves the problems discussed above withreference to the conventional devices.

[0007] Another object of the invention is to provide a closure,particularly for a glass container, which is able to compensate for thewide manufacturing tolerances on the glass.

[0008] It is a further object of the invention to provide a closurewhich is simple and economical to manufacture, particularly by molding.

[0009] According to a first aspect of the invention, these and otherobjects are achieved by a closure comprising a first screw threadcapable of cooperating with a second screw thread defined by a containerintended to receive said closure. It includes an elastically deformedpart capable, when the first and second screw threads are engaged, ofkeeping the closure bearing elastically on the container in at least onedirection which is oriented radially with respect to the closure, so asto improve the holding of the closure on the container. Thus, theseelastically deformed parts make it possible to compensate for the widetolerances arising in producing the screw thread borne by the container,particularly when this container is a glass container.

[0010] Advantageously, the elastically deformed parts are capable, whenthe first and second screw threads are engaged, of retaining at leastone portion of the first screw thread bearing elastically on at leastone corresponding portion of the second screw thread. The presence ofthese elastically deformed parts “locks” the screw thread when theclosure is being screwed on and unscrewed. In other words, it ispossible to obtain zero or practically zero functional clearance, thussubstantially improving the packing qualities.

[0011] In a particular embodiment, the closure comprises a lateral skirtbearing the first screw thread, the elastically deformed part consistingof at least one elastically deformed portion of the skirt whose radiusof curvature, at rest, differs from the radius of curvature of theremainder of the skirt. In such a configuration, the first screw threadis preferably produced on the interior wall of the lateral skirt, sothat it can be engaged with the second screw thread borne by theexterior wall of a neck formed by the container.

[0012] Preferably the elastically deformed parts consist of at least one“flat” formed by the skirt. Such a flat may, in the case of a closurewhich is obtained by molding a thermoplastic, be obtained by deformingthe lateral skirt as it leaves the mold and before the material hascompletely cooled. According to an advantageous alternative, the flat isalso obtained directly at the time of molding, by giving the mold theappropriate shape.

[0013] Preferably, the closure has two diametrically opposed elasticallydeformed parts. By achieving such symmetry, the holding of the closureon the container is improved and, in particular, the closure is bettercentered on the container. The comfort experienced in opening andclosing it is thus appreciably improved.

[0014] In another specific embodiment, the closure comprises atransverse wall, one edge of which is bent at 90° to form the lateralskirt bearing the first screw thread. Such a structure helps inimproving airtightness upon closure.

[0015] Preferably, each of the elastically deformed part is delimited atleast in part by a slot formed in the lateral skirt in the vicinity ofthe transverse wall. Thus, each slot is associated with an elasticallydeformed band. Each of the elastically deformed parts extends along theentire angular width of the corresponding slot, and is delimited by oneedge of the slot and by the free edge of the lateral skirt which liesfacing the slot.

[0016] Also, the lateral skirt preferably comprises at least twodiametrically opposed angular portions which have no screw thread. Anarrangement of this kind allows for easy mold-release of the closure byallowing a mold made in three parts, namely a central part lying facingthe thread-free parts, and two lateral parts. Mold release is achievedby first withdrawing the central part and by then bringing the twolateral parts closer together, so as to allow the threaded parts of theclosure to be released from the mold.

[0017] In a particularly advantageous embodiment, the closure comprisestwo slots situated outside of the angular portions which have no screwthread. Advantageously, the two slots are diametrically opposed.Advantageously also, the two slots are centered on an axis substantiallyperpendicular to an axis on which are centered the two portions whichhave no screw thread. These two slots can be released from the mold asthe two lateral parts of the mold are brought closer together.

[0018] In the case of a closure which is obtained by molding, it may bemade of a thermoplastic, particularly a polyethylene or a polypropylene.

[0019] The closure may be covered with an outer covering whose functionis mainly aesthetic, particularly to conceal the slots made in thelateral skirt of the closure. Furthermore, the outer covering makes itpossible to increase the rigidity of the structure bearing the screwthread. This covering also allows the use of materials whose aestheticsare particularly well-suited to applications such as the field ofcosmetics. The closure may be rendered integral with the outer coveringby any appropriate technique, particularly by bonding, welding orsnap-fastening.

[0020] According to a second aspect of the invention, there is alsoprovided a container comprising a closure according to the first aspect.

[0021] Advantageously, the container is made of glass. It may, inparticular, be ajar intended for packaging a care cream.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Apart from the provisions explained hereinabove, the inventionconsists in a certain number of other provisions which will be explainedhereafter with regard to non-limiting embodiments which are describedwith reference to the appended Figures, among which:

[0023]FIG. 1 depicts a general arrangement of a glass container equippedwith a closure according to the invention;

[0024] FIGS. 2A-2B depict a detailed view of the closure used with thecontainer of FIG. 1; and

[0025] FIGS. 3A-3C depict the main stages in molding/releasing from themold a closure as depicted in FIGS. 2A and 2B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0026] The container 1 depicted in FIG. 1 comprises a body 2, one end ofwhich is closed by an end wall 3 and the other end of which ends in aneck 4, a free edge 5 of which delimits an opening 6. The exteriorsurface of the neck 4 has a screw thread 7 capable, as will be seen ingreater detail later, of cooperating with a corresponding screw thread(11, FIG. 2A) of a closure 10. In this embodiment, the closure 10 has aninternal part 12 arranged inside an outer cover 13. The internal part 12may be mounted inside the outer covering 13 by bonding, welding orsnap-fastening.

[0027] The internal part 12 has a transverse wall 14, the edge of whichis bent at 90° to form a lateral skirt 15, on the internal surface ofwhich is the screw thread 11. The lateral skirt has two diametricallyopposed slots 24, 25 located in the vicinity of the zone where thetransverse wall 14 and the lateral skirt 15 meet, and which will bediscussed in greater detail later.

[0028]FIGS. 2A and 2B illustrate the part 12 of the closure 10 ingreater detail. As mentioned earlier, this part 12 comprises an end wallor transverse wall 14, the edge of which is bent at 90° to form alateral skirt 15. The internal surface of the lateral skirt 15 bears ascrew thread 11, formed of two parts 20, 21 separated by two skirtportions 22, 23 which have no screw thread. The two portions 22, 23 arediametrically opposed and centered on an axis X. The lateral skirt 15also has two slots 24, 25 passing through the thickness of the skirt 15.The two slots 24, 25 extend parallel to the plane of the end wall 14,and are formed substantially where the end wall 14 and the lateral skirt15 meet. In the embodiment depicted, the two slots 24, 25 are centeredon an axis Y perpendicular to the axis X. Thus, the upper edge 26 of theslot 24 delimits, with the free edge portion 27 of the skirt lyingfacing the slot 24, a first elastically deformed portion 28. Likewise,the upper edge 29 of the slot 25 delimits, with the free edge portion 30of the skirt lying facing the slot 25, a second elastically deformedportion 31.

[0029] As depicted in FIG. 2B, these two portions 28, 31 are, afterrelease from the mold and after the material has completely cooled,flattened using an appropriate tool, so as to form two diametricallyopposed flats. The flattening of these two portions 28, 31 may produce adisplacement δ of material which may range from a few tenths of a mm toseveral mm. After complete cooling, the two portions 28, 31 are fixed inthe position depicted in FIG. 2B. These two portions 28, 31 will allowthe part 12 of the closure to elastically grip the neck of the container1 and to do so in two diametrically opposed zones, thus compensating forany clearance associated with the manufacturing tolerances of the glassscrew thread 7 of the container 1. In other words, by virtue of thesetwo flattened portions 28, 31, there are produced two screw threadportions which have a diameter or radius of curvature which differs fromthe diameter or radius of curvature of the rest of the screw thread 11,thus making it possible, when the part 12 is screwed onto the neck 4 ofthe container, to achieve a thread-locking effect and thereby ensurethat the closure 10 firmly grips the container 1.

[0030] FIGS. 3A-3C illustrate one embodiment of the mold used forproducing the portion 12 of the closure depicted in FIGS. 2A and 2B. Asis apparent from these Figures, the mold consists of three parts: twolateral parts 100, 101, and a central part 102. Each of the lateralparts has the reliefs 103, 104 needed to produce the portions 20, 21 ofthe screw thread 11, and to produce the slots 24, 25. The lateral wall105 of the central part 102 has no reliefs.

[0031] After the part 12 has been molded (corresponding to the positionof the mold as depicted in FIG. 3A), the central part 102 is retractedas shown in FIG. 3B. Next, as depicted in FIG. 3C, the lateral parts101, 103 are brought closer together so as to disengage the reliefs 103,104 from the corresponding recessed parts formed in the molded part,thus allowing the part 12 to be released from the mold. The part 12, asit leaves the mold, is as depicted in FIG. 2A. Before the materialcools, the two portions 28 and 31 are flattened in the way depicted inFIG. 2B. The cover 13 is then snap fitted over the part 12.

[0032] According to an advantageous alternative, the flattened shape inthe region of the two elastically deformed bands 28, 31 is a directresult of molding, by giving the lateral parts 100 and 101 of the moldthe corresponding flattened shape. Thus, the part leaves the molddirectly with the required shape.

[0033] In the foregoing detailed description, reference has been made topreferred embodiments of the invention. It is obvious that variationsmay be made thereto without departing from the spirit of the inventionas claimed hereinafter.

1. A closure comprising: a closure part; a first screw thread on saidclosure part capable of cooperating with a second screw thread on acontainer to receive said closure; an elastically deformed part on saidclosure part at a location such that at least a portion of said firstscrew thread bears elastically on the container when said first andsecond screw threads are engaged.
 2. The closure according to claim 1,wherein said elastically deformed part is positioned to bear elasticallyon the container in at least one direction which is oriented radiallywith respect to the closure.
 3. The closure according to claim 1,wherein said elastically deformed part is positioned to bear elasticallyon at least one corresponding portion of the second screw thread.
 4. Theclosure according to claim 1, comprising two diametrically opposed onesof said elastically deformed parts.
 5. The closure according to claim 1,wherein said closure part comprises a lateral skirt bearing said firstscrew thread, wherein said elastically deformed part comprises at leastone elastically deformed portion of the skirt whose radius of curvature,at rest, differs from the radius of curvature of the rest of the skirt.6. The closure according to claim 4, wherein said elastically deformedpart comprises at least one flat part of the skirt.
 7. The closureaccording to claim 5, wherein said closure part further comprises atransverse wall, one edge of which is bent at 90° to form said lateralskirt.
 8. The closure according to claim 7, wherein each of saidelastically deformed parts is delimited at least in part by a slotformed in the lateral skirt in the vicinity of the transverse wall. 9.The closure according to claim 5, wherein said lateral skirt has atleast two diametrically opposed angular portions which have no screwthread.
 10. The closure according to claim 8, wherein said skirtcomprises two slots situated outside of angular portions which have noscrew thread.
 11. The closure according to claim 10, wherein said slotsare diametrically opposed and centered on an axis perpendicular toanother axis on which the two portions which have no screw thread arecentered.
 12. The closure according to claim 1, formed of a moldedthermoplastic.
 13. The closure according to claim 12, wherein the moldedthermoplastic comprises one of a polyethylene and a polypropylene. 14.The closure according to claim 1, further comprising an outer coveringon the closure part.
 15. A container comprising: a bottle; and a closurepart; a first screw thread on said closure part capable of cooperatingwith a second screw thread on the bottle; an elastically deformed parton said closure part at a location such that at least a portion of saidfirst screw thread bears elastically on the bottle when said first andsecond screw threads are engaged.
 16. The container according to claim15, wherein said container is made of glass.